The most substantiated evidence for modification of disease susceptibility and/or progression of periodontal disease arises from studies on Type I and Type II (insulin-dependent and non-insulin-dependent) diabetes mellitus populations.
It has to be realized that the impact of diabetes on periodontal diseases has been documented in patients with untreated periodontal disease, while, as of today, no clear evidence is available for treated patients. It is reasonable, however, to assume that the influence of the systemic conditions may also affect recurrence of disease.
In assessing the patient’s risk for disease progression, systemic factors, if known, are only considered as the fifth risk indicator for recurrent disease in the functional diagram of risk assessment. In this case, the area of high risk is marked for this vector. If not known or absent, systemic factors are not taken into account for the overall evaluation of risk.